Nutrition + some biological molecules Flashcards
balanced diet
a diet which contains fat, water, carbohydrates, proteins, vitamins, minerals and fibre in the correct proportions.
Bread, pasta, rice are a good source of which carbohydrate?
Starch
This nutrient can be broken down to provide cells with a source of short-term energy, what is it?
Carbohydrate
Meat, fish and cheese and eggs are a good source of which nutrient?
Protein
Red meat, oils, nuts and margarine are a good source of which nutrients?
Fats and lipids
Fat/lipid
These nutrients
form cell membranes
are a long term store of energy
provide insulation
protect organs from mechanical shock.
Fresh fruit and vegetables are a good source of which vitamin?
Sources of vitamin C
what is vitamin C needed for?
Is needed to bonds tissue cells together that line surfaces such as the mouth. keeps tissues in good repair.
Fish liver oils. It is also made in the skin in the presence of sunlight, what is it?
Sources of vitamin D
Calcium
Mineral used to make strong bones and teeth.
Iron
Red meat, liver, eggs, some vegetables (e.g. spinach)
Forms part of the haemoglobin in red blood cells and helps carry oxygen
food test for starch
Iodine = orange - brown
positive test = orange/brown to blue/black
negative = orange - brown (no change)
food test for protein
add biuret solution to food sample
positive test = blue to violet/purple
food test for lipids
ethanol added to food sample and mix
ethanol is added to an equal volume of cold water
positive test = cloudy emulsion
food test for vitamin C
add 1cm3 of DCPIP solution
positive test = blue colour of dye disappearing
food test for reducing sugar
Benedict’s solution
negative = blue
positive = blue - orange/red
Calorimeter
Measures the amount of energy given out by a burning food sample by using it to heat up a known mass of water
Kilojoules (kJ)
The unit used to measure energy
how much energy do proteins release?
released approximately the same amount of energy in respiration as carbohydrates but are only respired in condition of starvation
how much energy do lipids release?
release approximately twice the amount of energy in respiration as carbohydrates
what are proteins composed of?
long chain of amino acids bound to each other
what are lipids composed of
of one glycerol molecule and three fatty acids bound to each other
what is starch composed of?
of a long chain of glucose molecules bound to each other and produced in plants
what is glycogen composed of?
of a long chain of glucose molecules bound to each other and produced in animals
